see, understanding the nature of these explosive devices that he was comfortable and i probably felt a little bit of political pressure to call what it it is, which is an act of terror. the real trick here is the white house wanting to calibrate the judgment, not wanting to jump to conclusions and also wanting to send a message of national resilience which is something you've heard consistently not just from the white house but from homeland and counterterrorism officials for the last couple of years. >> ifill: don borrelli, as the nation struggles to find the balance between that kind of resiliency and awareness of what might be going on, does it matter that this is a different kind of venue? that is to say a big spectator event where someone knew there was going to be a lot of attention paid? >> well, there's -- you know, it's a double-edged sword. the fact that there are so many spectators, so many cameras that gives the investigative team that many more leads because, as we've heard, there's been so much assistance from the citizens sending in their films, their stills, the video cameras.